Really great game! One of my favorites I've played thus far.
What definitely stands out above all else is the art and animation. I loved the animatic-styled opening. The in game animations and art look great too. Especially all the biblically accurate angels.
The gameplay was solid, but maybe a tad sluggish for my tastes. I do wish I could hold down the fire button. Though the game does look amazing, one thing I'd like to see is a little more "juice". More feedback/effects when hitting and defeating enemies in particular. The unremarkable way enemies are hit and defeated adds to the slow feel of the game. I think a little more polish in that area could really add to the game.
I had similar feelings about the audio. It wasn't bad at all, but could be a little more intense or impactful. The music was fine, but it also stopped playing for me sometime during Wave 3, and the game was SFX only till the end.
I made it to the current end, with a score of 25100. Even though I do think there's some room for improvement, this is still a really great game as-is. I'll be interested to see the boss when you finish it. Impressive work!